The invention generally relates to a voltage regulator.
A DC-to-DC voltage regulator typically is used to convert a DC input voltage to either a higher or a lower DC output voltage. One type of voltage regulator is a switching regulator that is often chosen due to its small size and efficiency. The switching regulator typically includes one or more switches that are rapidly opened and closed to transfer energy between an inductive element (a stand-alone inductor or a transformer, as examples) and an input voltage source in a manner that regulates the output voltage.
In a power supply system, capacitive charge pumps may be used to produce multiple supply voltages from an output voltage that is provided by a particular voltage regulator. For example, capacitive charge pumps may be used to produce high supply voltages for non-volatile memory operations. The scaling of power supplies to maintain reliable electric fields has led to more stages in capacitive charge pumps and less efficiency for the charge pumps. Furthermore, due to the increased number of stages, the charge pumps typically consume considerable die area.
Thus, a power supply system presents challenges relating to generating multiple supply voltages. Therefore, there is a continuing need for better ways to produce multiple supply voltages.